package IO;

import java.io.*;
import java.nio.file.Files;
import java.util.Scanner;

public class Demo20 {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        System.out.println("请输入想要搜索的路径:");
        String rootPath = scanner.next();
        File rootFile = new File(rootPath);
        if(!rootFile.isDirectory()){
            System.out.println("搜索的路径有误！");
            return ;
        }

        System.out.println("请输入搜索的关键字:");
        String key = scanner.next();

        //进行递归
        scan(rootFile,key);
    }

    private static void scan(File rootFile, String key) {
        if(!rootFile.isDirectory()){
            return ;
        }
        File[] files = rootFile.listFiles();
        if(files == null || files.length == 0){
            return ;
        }
        for (File f : files) {
            if(f.isFile()){
                //进行后续的查询操作
                doSreach(f,key);
            }else{
                //进行递归
                scan(f,key);
            }
        }
    }

    private static void doSreach(File f, String key) {
        //打开文件，读取文件内容
        //判定文件内容中是否包含 key

        StringBuilder stringBuilder = new StringBuilder();

        try(Reader reader = new FileReader(f)){
            char[] buffer = new char[1024];

            while(true){
                int n = reader.read(buffer);
                if(n == -1){
                    break ;
                }
                String s = new String(buffer,0,n);
                stringBuilder.append(s);
            }

        }catch(IOException e){
            e.printStackTrace();
        }

        if(stringBuilder.indexOf(key) == -1){
            //未找到
            return ;
        }
        //找到了
        System.out.println("找到匹配的文件：" + f.getAbsolutePath());
    }
}
